Patent GB-489820-A (GB)
Title: Improvements in the manufacture of wire netting by means of electric resistance welding
IPC: B21F27/10
Filed: 1937-10-09
Abstract: 489,820. Making wire netting. KRAMER, W. Oct. 9, 1937, No. 27493. Convention date, Oct. 16, 1936. [Classes 83 (ii) and 83 (iv)] Welding; shearing.-In making wire netting by electric resistance welding, the position of the longitudinal wires relatively to the electrodes or vice versa, is altered in the transverse direction after each weld or after a series of welds in order to obtain more even wear of the electrodes and thus a more uniform fabric. The position of the transverse wires to be welded may also be similarly altered in a longitudinal direction. The longitudinal wires 1 are fed to the electrodes 4, 5 through apertures 2 in a guide bar 3, which has slots 13 and is reciprocated transversely by an eccentric 17 on a shaft 19 rotated step-by-step by ratchet mechanism 18, 21, 20 from a rod 22 which may be connected to the reciprocating electrode support 11 or to a part which performs a stroke only after a number of strokes of the support so as to reduce the sinuosity of the fabric. The shaft 19 is provided with a brake 51. The electrodes each consist of a number of sections connected by slots 9 and bolts 8 to their supports 10, 11 and independently adjustable by bolts 12 so as to obtain equal pressure at all joints. In order to vary the position of the subsequent transverse wires 6 relatively to the electrodes, the wires are fixed by clamps against positioning members 7 which are moved about pivots 24 by eccentrics 26 rotated by ratchet mechanism 27, 35, slotted lever 34 and a pair of sleeves 30,29 with cam-shaped ends 36,37. The sleeve 30 is loose on the shaft 19 and the sleeve 29 fixed thereon. The number of cam surfaces on the sleeves determines the number of rocking movements of the lever 34 for each rotation of the shaft 19. In order that the ends of the transverse wires may always be severed flush with the sides of the fabric, the cutting mechanisms are given a transverse movement corresponding to that of the longitudinal wires. For this purpose each set of cutters comprises cutter discs a<1>, a<2>, d and a guide disc e, Fig. 3, mounted on three shafts 50, the central shaft of which is driven from the take-up mechanism, the cutter a<1> being pressed against the discs d, e and the cutter a<2> against a ring 58 fixed on the central shaft, by a spring c. The central shaft is moved axially so as to move the cutters transversely by a cam 52 on the shaft 19 and a slotted lever 53 engaging studs 56 on a slide ring 57 mounted between rings 58, 59 fixed to the shaft. The cutters a2 come into operation only when a wire netting is to be divided into narrower strips, the distance between the cutters a<1>, a<2> being equal to the width of a free mesh space. The electrodes are operated by a channel bar 39 through rods 41 reciprocated by cranks or eccentrics. The electrode supports are provided with bolts 38 having adjustable collars 42 secured thereon which are pressed down by weak springs 43 so that the electrodes apply a light pressure during heating. In order to complete the welds the lower flanges 39 engage collars 47 guided by slots 46 and between which and adjustable collars 48 fixed on the bolts strong springs 44 are mounted. The springs 44 may be replaced by weights. The eccentrics 17, 26, 52 may be replaced by cranks. Specification 457,519 is referred to.